Particle drilling method

ABSTRACT

A particle drilling method includes steps of: (a) injecting particles, namely injecting slurry and the particles into a well through an injection device; (b) recovering the particles, specifically including steps of: enabling a mixture of particles, rock debris and slurry returned from the well to directly flow into a magnetic separator ( 10 ) by a pipeline through a rotational control head at a drill floor; sending separated particles into a storage tank by the magnetic separator ( 10 ); and sending a mixture of rock debris and slurry into a slurry tank ( 11 ); and (c) injecting the particles in the storage tank into the well through the injection device for drilling again, so as to form a drilling circulation. The above method effectively solves a problem of many slurry leakage points in prior arts and greatly reduces an environmental pollution risk.

CROSS REFERENCE OF RELATED APPLICATION

This is a U.S. National Stage under 35 U.S.C 371 of the International Application PCT/CN2016/089442, filed Jul. 8, 2016, which claims priority under 35 U.S.C. 119(a-d) to CN 201510399376.9, filed Jul. 9, 2015.

BACKGROUND OF THE PRESENT INVENTION Field of Invention

The present invention relates to a technical field of oil-gas drilling engineering, and more particularly to a particle drilling method.

Description of Related Arts

The conventional drilling method realizes the mechanical rock breaking through utilizing the bit pressure and the rotation of the drill bit at the well bottom, so as to achieve drilling. With the above conventional drilling method, when meeting the deep hard formation and the strong-abrasive formation, the rock breaking merely relies on the mechanical action of the drill bit, and the function of the slurry is only to carry the rock debris, which is unable to realize the combined rock breaking effect of water power and mechanical engineering, having the problems of slow drilling speed, long period and high cost. In recent years, the particle impact drilling technology as a revolutionary speed-up technology has been widely applied. The particle impact drilling technology is a drilling technology which injects spherical steel particles having a diameter of 1-3 mm into the well bottom, so as to assist in breaking the deep hard formation and the strong-abrasive formation. An important factor to determine whether the particle impact drilling effect is good or bad is the particle injection device. The conventional particle injection device generally adopts the single high-pressure tank injection structure, which is unable to realize the particle continuous injection; in addition, because the high-pressure tank has the relatively heavy weight and large volume, the transportation is inconvenient, the high-pressure area has a wide coverage, and the safety risk is high; moreover, the pressure withstood by per unit floor area is high and the foundation needs to be strengthened through the cement solidification, which is time-consuming and has the high cost. Therefore, it is urgent to produce an injection device which is able to realize the particle continuous injection, is convenient to transport and has the high safety, so as to meet the on-site demands.

The Chinese patent publication of CN 203742449U, published on Jul. 30, 2014, disclosed a particle vertical injection device, comprising a high-pressure container, wherein: an inlet pipe is arranged at the upper part of the high-pressure container; an outlet pipe is arranged at the lower part of the high-pressure container; an inclined discharge port is arranged on the outlet pipe; a rotation shaft is arranged inside the high-pressure container; helical teeth are arranged on the rotation shaft; an upper sealing member and a lower sealing member are arranged respectively between the rotation shaft and the top part of the high-pressure container and between the rotation shaft and the bottom part of the high-pressure container; bearings are arranged between the upper sealing member and the rotation shaft and between the lower sealing member and the rotation shaft; an upper end cover and a lower end cover are arranged respectively at the outer sides of the upper and lower bearings; a pressure relief hole is axially provided on the upper end cover; a bottom part of the rotation shaft is connected to a motor through a shaft coupling; the motor is fixed on an outrigger through a support rod; the high-pressure container is fixed on the outrigger; the inclined discharge port is connected to a high-pressure hydraulic valve; and the high-pressure hydraulic valve is connected with a high-pressure tee. The disclosed particle vertical injection device enables the particles to fall down evenly and avoids the particles being accumulated at the bottom part of the high-pressure container. However, the adopted single high-pressure container is merely able to realize the particle intermittent injection and unable to realize the particle continuous injection; the adopted high-pressure container has the relatively high weight and large volume, so that the pressure withstood by per unit floor area is high and the foundation needs to be strengthened through the cement solidification, which is time-consuming, expensive and inconvenient to transport; moreover, the high-pressure area of the device has a wide coverage, and the safety risk is high.

The Chinese patent publication of CN 103195363A, disclosed on Jul. 10, 2013, disclosed a negative-jet-typed particle impact drilling injection device, comprising a high-pressure particle injection tank, wherein: a feed port is arranged at a top part of the high-pressure particle injection tank and a discharge port is arranged at a bottom part of the high-pressure particle injection tank; a balance pressure jet pipe is arranged at a side of the feed port; a jet anti-blocking sprayer is arranged at one end of the balance pressure jet pipe, and the other end of the balance pressure jet pipe is arranged at a top part of a main pipe; the jet anti-blocking sprayer is arranged at the bottom part of the high-pressure particle injection tank; a negative-pressure particle injection pipe is arranged at a bottom part of the discharge port; a nozzle is arranged at an end of the negative-pressure particle injection pipe and is interconnected with the main pipe; an adjusting pipe is arranged at a bottom part of the main pipe, and an end of the adjusting pipe is interconnected with an outlet of the negative-pressure particle injection pipe; and an adjusting valve is arranged inside the adjusting pipe. The disclosed negative-jet-typed particle impact drilling injection device adopts an automatically rotational jet anti-blocking sprayer, which realizes the omnidirectional multi-angle stirring of the discharge port of the high-pressure particle injection tank and is able to solve the blocking problem at the bottom part of the high-pressure particle injection tank. However, the adopted single high-pressure container is merely able to realize the particle intermittent injection and unable to realize the particle continuous injection; the adopted high-pressure container has the relatively high weight and large volume, so that the pressure withstood by per unit floor area is high and the foundation needs to be strengthened through the cement solidification, which is time-consuming, expensive and inconvenient to transport; moreover, the high-pressure area of the device has a wide coverage, and the safety risk is high.

The Chinese patent publication of CN 102619468A, published on Aug. 1, 2012, disclosed a particle impact drilling injection device, comprising a ground high-pressure main pipeline, a flow diversion pipeline, a flow diversion pipeline control valve, a steel particle storage tank, a hydraulic (or manual) charging valve, a storage tank pressure relief pipeline, a storage tank pressure relief control valve, steel particles, a screw propeller, a steel particle injection control valve and a flow limiting device, wherein: the flow limiting device is arranged behind the flow diversion pipeline; the flow diversion pipeline control valve is arranged between the ground high-pressure main pipeline and the steel particle storage tank; the storage tank pressure relief control valve is arranged between the steel particle storage tank and a drilling liquid pool; the screw propeller is arranged below the steel particle storage tank; and the steel particle injection control valve is arranged between the screw propeller and the ground high-pressure main pipeline. The disclosed particle impact drilling injection device adopts a left set and a right set of injection devices which are completely same and mutually independent. Through the alternate and repeated operation of the two sets of the injection devices, the particle continuous injection is realized. However, in the actual application, the particles in the screw propeller of the injection device are easy to be agglomerated and block the screw propeller, so that it is failed to realize the normal injection of the particles; the adopted steel particle storage tank has the relatively high weight and large volume, so that the pressure withstood by per unit floor area is high and the foundation needs to be strengthened through the cement solidification, which is time-consuming, expensive and inconvenient to transport; moreover, the high-pressure area of the device has a wide coverage, and the safety risk is high.

In recent years, the particle drilling method has been widely applied. The main related devices of the particle drilling method are the injection device and the recovery device, wherein the recovery device mainly comprise a drilling crew vibrating screen, a jet mixer, a magnetic separator, a vibrating screen, a rock debris storage hopper, a slurry tank and a static storage tank. The whole drilling process comprises steps of: injecting the mixture of particles and slurry into the well through the injection device for drilling; the mixture of particles, rock debris and slurry returned from the well passing respectively through the drilling crew vibrating screen, the jet mixture and the magnetic separator; separating the particles from the mixture of rock debris and slurry by the magnetic separator, and pumping the particles into the static storage tank for reservation; after the remaining mixture of rock debris and slurry passes through the vibrating screen for being screened, the rock debris falling into the rock debris storage hopper, and the slurry falling into the slurry tank for reservation; and finishing a drilling circulation.

Through the above particle drilling method, the jet mixer, the vibrating screen, the rock debris storage hopper of the recovery device and the associated low-pressure pipeline easily lead to the leakage of the drilling fluid, causing the environmental pollution; moreover, the number of the required devices is large, the installation positions of the devices are dispersed, the installation is complex, the time consumption is relatively long, and the maintenance cost is relatively high.

The Chinese patent publication of CN 102022078A, published on Apr. 20, 2011, disclosed a new drilling method. The pump-out pipeline of the drilling pump is connected to a set of particle injection system, so that the high-pressure slurry to be injected into the well is continuously mixed with the hard particles having the particle diameter in a range of 2-8 mm, then flows down along the drill column to the drill bit, and accelerates at the bit port to hit the rock at a greatly high speed, thereby achieving the combined rock breaking effect of mechanical engineering and particle impact and increasing the drilling speed at the hard formation. The slurry return pipeline at the well mouth is connected to a set of particle separating system, so that the metal particles are separated from the mixed liquid returned from the well bottom for recycling.

According to the above disclosed drilling method, in order to increase the particle injection efficiency, two sets of the injection devices which are able to work independently are adopted. However, the number of the involved devices is relatively large, the structure is complex, the installation is inconvenient, and the operation is not easy. The particles in the involved screw propeller are easy to be agglomerated and block the screw propeller, so that it is failed to realize the normal injection of the particles; the adopted injection devices have the relatively high weight and large volume, so that the pressure withstood by per unit floor area is high and the foundation needs to be strengthened through the cement solidification, which is time-consuming, expensive and inconvenient to transport; the high-pressure area of the devices has a wide coverage, and the safety risk is high; the two sets of injection devices are independent to each other and unable to be organically connected together, which increases the cooperation difficulty between the particle separating system and the particle transporting system and substantially limits the particle drilling efficiency.

SUMMARY OF THE PRESENT INVENTION

An object of the present invention is to provide a particle drilling method to solve above defects in prior arts. The present invention enables a mixture of particles, rock debris and slurry returned from a well to directly flow into a magnetic separator through an exit device at a well mouth with utilizing liquid energy, so as to separate and storage the particles, which effective solves a problem of many slurry leakage points in the prior arts caused by directly pumping the rock debris and the slurry into a drilling crew vibrating screen and greatly decreases an environmental pollution risk.

The present invention is realized through following technical solutions.

A particle drilling method comprises steps of particle injection and particle recovery, wherein:

the step of particle injection specifically comprises a step of injecting slurry and particles into a well through an injection device;

the step of particle recovery specifically comprises steps of: enabling a mixture of particles, rock debris and slurry returned from the well to directly flow into a recovery device by a pipeline through an exit device at a well mouth of a drill floor with liquid energy; sending separated particles into a storage tank by a magnetic separator of the recovery device; and sending a mixture of rock debris and slurry into a slurry tank; and

after the steps of particle injection and particle recovery, the particles in the storage tank are transported to the injection device and then injected into the well through the injection device for drilling again, so as to form a particle impact drilling circulation.

In the step of particle injection, a particle injection speed is 0.5-10 kg/s.

In the step of particle injection, a particle injection pressure is 5-55 MPa.

The storage tank is a rotational storage tank, comprising a tank body, blades arranged in the tank body, a support frame, a screen barrel and a motor driving the tank body to rotate, wherein: the blades and the support frame are fixed on an inner wall of the tank body; and the screen barrel is connected with the blades through the support frame.

The injection device is a double-injection-pump continuous injection device, comprising a particle mixing hopper which is connected with a drilling vertical pipe through a high-pressure pipeline, wherein: a reversing pipe is arranged in the particle mixing hopper; the reversing pipe is connected with a swinging hydraulic cylinder which drives the reversing pipe to swing from left to right; a first transporting cylinder and a second transporting cylinder are connected with the particle mixing hopper; a first end of the reversing pipe is interconnected with the high-pressure pipeline, and a second end of the reversing pipe is interconnected with the first transporting cylinder or the second transporting cylinder. When injecting the particles, a first hydraulic cylinder, a second hydraulic cylinder and the swinging hydraulic cylinder are firstly started; the first hydraulic cylinder starts an addition stroke, the swinging hydraulic cylinder swings the reversing pipe to the second transporting cylinder so that the reversing pipe is interconnected with the second transporting cylinder, and the particles and the slurry enter the first transporting cylinder; meanwhile, the second hydraulic cylinder starts a compression stroke that the particles and the slurry in the second transporting cylinder are injected into the high-pressure pipe through the reversing pipe to enter an inner well circulation; the first hydraulic cylinder starts a compression stroke after ending the addition stroke, and the second hydraulic cylinder starts an addition stroke, so as to continuously inject the particles through an alternate operation.

The swinging hydraulic cylinder comprises cylinder bodies, pistons, piston rods, a swinging rod and a spline connected with the swinging rod, wherein: the pistons are connected with the swinging rod through the respective piston rods; and the reversing pipe is connected with the spline.

The high-pressure pipeline is connected with an arrow-shaped check valve.

The slurry tank consists of a cylindrical tank body and a conical tank body, wherein the conical tank body is arranged below the cylindrical tank body; and, the conical tank body and the cylindrical tank body are integrated together.

The exit device comprises a rotational sprayer and a rotational control head connected with the rotational sprayer.

Working principles of the present invention are described as follows.

During the particle impact drilling process, the separated and stored particles in the recovery device of particle drilling are firstly added into the particle mixing hopper through a screw conveyor, wherein an addition speed of the particles is controlled through a screw rotation speed of the screw conveyor; the slurry is pumped into the particle mixing hopper through a slurry pump; an occupied volume of a mixture of particles and slurry in the particle mixing hopper is maintained at ½-⅔ of the volume of the particle mixing hopper; when the occupied volume of the mixture of particles and slurry reaches ½ of the volume of the particle mixing hopper, the first hydraulic cylinder and the second hydraulic cylinder are started; the first hydraulic cylinders starts the addition stroke, meanwhile the swinging hydraulic cylinder is started and swings the reversing pipe to the second transporting cylinder so that the reversing pipe is rapidly interconnected with the second transporting cylinder, and the mixture of particles and slurry in the particle mixing hopper is added into the first transporting cylinder; at the same time, the second hydraulic cylinder starts the compression stroke and extrudes the mixture of particles and slurry which comes from the particle mixing hopper and is stored in the second transporting cylinder, the mixture of particles and slurry is injected into the high-pressure pipeline through the reversing pipe and finally enters the inner well circulation; when a second piston moves to a limiting position, the second hydraulic cylinders ends the compression stroke and starts the addition stroke, the swinging hydraulic cylinder swings the reversing pipe to the first transporting cylinder so that the reversing pipe is interconnected with the first transporting cylinder, the first hydraulic cylinders ends the addition stroke and starts the compression stroke, and the mixture of particles and slurry in the first transporting cylinder is injected into the high-pressure pipeline through the reversing pipe, so as to finally enter the inner well circulation, which realizes the alternate operation of the first transporting cylinder and the second transporting cylinder and enables the particles to be continuously injected into the well; the mixture of slurry, rock debris and particles, returned from the well, directly flows into the magnetic separator through the rotational control head and the pipeline, the magnetic separator separates the particles from the mixture of slurry, rock debris and particles and transports the separated particles to the rotational storage tank for storage through a horizontal conveyor, the rock debris and the slurry fall down into the slurry tank below the magnetic separator, and the mixture of rock debris and slurry in the slurry tank is directly pumped into the drilling crew vibrating screen through the slurry pump and the pipeline, thereby realizing the separation and recovery of the particles; the separated particles are stored in the rotational storage tank and then directly pumped into the particle mixing hopper through the screw conveyor. Through the above process, recycling of the particles during the whole drilling process is realized.

Beneficial effects of the present invention are mainly shown in following aspects.

Firstly, according to the present invention, the step of particle injection is to inject the slurry and the particles into the well through the injection device; the step of particle recovery is to enable the mixture of particles, rock debris and slurry returned from the well to directly flow into the recovery device by the pipeline through the exit device at the well mouth of the drill floor with the liquid energy, then send the separated particles into the storage tank by the magnetic separator of the recovery device, and send the mixture of rock debris and slurry into the slurry tank; after the steps of particle injection and particle recovery, the particles in the storage tank are transported to the injection device and injected into the well through the injection device for drilling again, so as to form the particle impact drilling circulation. Through the step of particle recovery, the mixture of particles, rock debris and slurry returned from the well directly flows into the magnetic separator of the recovery device for particle separation, which simplifies a particle screening process. Because the slurry and the rock debris do not contain ferromagnetic materials, the particles are easily separated by the magnetic separator, having advantages of high separation efficiency and good separation effect. After separating the particles, the magnetic separator directly transports the separated particles to the storage tank for recycling. Compared with the prior arts, under a premise of not changing a conventional drilling process, a particle recovery process is simplified; devices which easily cause a slurry leakage, such as a jet mixer, an associated low-pressure pipeline, a vibrating screen and a rock debris storage hopper, are avoided; an installation efficiency, an operation convenience and a maintenance convenience of the recovery system are effectively improved; a working efficiency of particle impact drilling is greatly increased; a problem of many slurry leakage points, caused by firstly pumping the mixture of rock debris and slurry into the drilling crew vibrating screen and then transporting to the recovery device, is effectively solved; and an environmental pollution risk is greatly reduced.

Secondly, according to the present invention, in the step of particle injection, the particle injection speed is 0.5-10 kg/s; through adopting the specific injection speed, performance of drilling fluid during the drilling process is guaranteed; and at the specific injection speed, a particle impact frequency of the particles hitting the rock is larger than 10 million times per minute, which achieves a good impact rock breaking effect and increases a drilling efficiency.

Thirdly, according to the present invention, in the step of particle injection, the particle injection pressure is 5-55 MPa; at the specific pressure range, the injection speed of the particles is effectively guaranteed, the drilling efficiency is increased, the drilling vertical pipe is effectively avoided being damaged, and a working stability of particle drilling is guaranteed.

Fourthly, according to the present invention, the storage tank is the rotational storage tank, comprising the tank body, the blades in the tank body, the support frame, the screen barrel and the motor driving the tank body to rotate, wherein: the blades and the support frame are fixed on the inner wall of the tank body; and the screen barrel is connected with the blades through the support frame. Through the rotational storage tank having the unique structure, when rotating positively, dynamic storage is realized, and the particles are avoided being agglomerated during a rotational storage process; when rotating negatively, particle discharging is realized, and the blades enable the particles to be uniformly discharged out.

Fifthly, according to the present invention, the injection device is the double-injection-pump continuous injection device, comprising the particle mixing hopper which is connected with the drilling vertical pipe through the high-pressure pipeline, wherein: the reversing pipe is arranged in the particle mixing hopper; the reversing pipe is connected with the swinging hydraulic cylinder which drives the reversing pipe to swing from left to right; the first transporting cylinder and the second transporting cylinder are connected with the particle mixing hopper; the first end of the reversing pipe is interconnected with the high-pressure pipeline, and the second end of the reversing pipe is interconnected with the first transporting cylinder or the second transporting cylinder. When injecting the particles, the first hydraulic cylinder, the second hydraulic cylinder and the swinging hydraulic cylinder are firstly started; the first hydraulic cylinder starts the addition stroke, the swinging hydraulic cylinder swings the reversing pipe to the second transporting cylinder so that the reversing pipe is interconnected with the second transporting cylinder, and the particles and the slurry enter the first transporting cylinder; meanwhile, the second hydraulic cylinder starts the compression stroke that the particles and the slurry in the second transporting cylinder are injected into the high-pressure pipeline through the reversing pipe to enter the inner well circulation; the first hydraulic cylinder starts the compression stroke after ending the addition stroke, and the second hydraulic cylinder starts the addition stroke, so that the continuous injection is realized through the alternate operation, which guarantees a continuity of particle injection in the well, avoids the first transporting cylinder and the second transporting cylinder being blocked due to particle deposition, and effectively increases the working efficiency of particle impact drilling. In the double-injection-pump continuous injection device, merely the first transporting cylinder, the second transporting cylinder and the reversing pipe are in a high-pressure state. Compared with the prior arts, the injection device with the high-pressure tank and the associated screw conveyor is replaced, the injection process is optimized, the problem of the particle intermittent injection of the single high-pressure tank is solved, and the particle continuous injection is realized. Meanwhile, the problem of the difficult particle injection caused by easily agglomerated and blocked particles in the screw conveyor and the problems of the inconvenient transportation, installation and operation, the time consumption and the high cost caused by the relatively heavy weight and large volume of the associated device of the high-pressure tank are solved, the working efficiency of particle drilling is increased, the high-pressure area of the injection device is greatly reduced, and the safety is improved.

Sixthly, according to the present invention, the swinging hydraulic cylinder comprises the cylinder bodies, the pistons, the piston rods, the swinging rod and the spline connected with the swinging rod, wherein the pistons are connected with the swinging rod through the respective piston rods; and the reversing pipe is connected with the spline. Through the swinging hydraulic cylinder having the above specific structure, the swinging rod enables the reversing pipe to change a direction flexibly, having an advantage of flexibly reversing; and moreover, through structures of the spline and the swinging rod, a service life is lengthened.

Seventhly, according to the present invention, the arrow-shaped check valve is connected with the high-pressure pipeline. Through adopting the arrow-shaped check valve, the mixture of particles and slurry is able to smoothly enter the well through the high-pressure pipeline; and, the mixture of particles and slurry is avoided reversely entering the first transporting cylinder or the second transporting cylinder, which effectively avoids a damage to people caused by the slurry leakage during the particle injection process and further improves the safety.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a structural sketch view of a drilling device according to the present invention.

FIG. 2 is a structural sketch view of a connection between a double-injection-pump continuous injection device and a drill floor according to the present invention.

FIG. 3 is a structural sketch view of a swinging hydraulic cylinder according to the present invention.

FIG. 4 is a structural sketch view of a connection between a double-injection-pump continuous injection device and the drill floor according to a fourth preferred embodiment of the present invention.

FIG. 5 is a structural sketch view of a reversing pipe according to a fifth preferred embodiment of the present invention.

FIG. 6 is a structural sketch view of a rotational storage tank according to a sixth preferred embodiment of the present invention.

In figures: 1: first hydraulic cylinder; 2: second hydraulic cylinder; 3: swinging hydraulic cylinder; 4: reversing pipe; 5: first piston; 6: first transporting cylinder; 7: second piston; 8: second transporting cylinder; 9: high-pressure pipeline; 10: magnetic separator; 11: slurry tank; 12: rotational storage tank; 13: cylinder body; 14: piston; 15: piston rod; 16: swinging rod; 17: spline; 18: arrow-shaped check valve; 19: seal ring; 20: tank body; 21: blade; 22: support frame; 23: screen barrel; 24: motor; 25: particle mixing hopper; 26: rotational control head; 27: rotational sprayer; and 28: exit device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT First Preferred Embodiment

Referring to FIG. 1, a particle drilling method comprises steps of particle injection and particle recovery, wherein: the step of particle injection is to inject slurry and particles into a well through an injection device; the step of particle recovery is to enable a mixture of particles, rock debris and slurry returned from the well to directly flow into a recovery device by a pipeline through an exit device 28 at a well mouth of a drill floor with liquid energy, then send separated particles into a storage tank by a magnetic separator 10 of the recovery device, and send a mixture of rock debris and slurry into a slurry tank 11; after the steps of particle injection and particle recovery, the particles in the storage tank are transported to the injection device and injected into the well through the injection device for drilling again, so as to form a particle impact drilling circulation.

The first preferred embodiment illustrates a most basic implementation method, and the adopted injection device and storage tank are conventional. Through the step of particle recovery, the mixture of particles, rock debris and slurry returned from the well directly flows into the magnetic separator of the recovery device for particle separation, which simplifies a particle screening process. Because the slurry and the rock debris do not contain ferromagnetic materials, the particles are easily separated by the magnetic separator, having advantages of high separation efficiency and good separation effect. After separating the particles, the magnetic separator directly transports the separated particles to the storage tank for recycling. Compared with the prior arts, under a premise of not changing a conventional drilling process, a particle recovery process is simplified; devices which easily cause a slurry leakage, such as a jet mixer, an associated low-pressure pipeline, a vibrating screen and a rock debris storage hopper, are avoided; an installation efficiency, an operation convenience and a maintenance convenience of the recovery system are effectively improved; a working efficiency of particle impact drilling is greatly increased; a problem of many slurry leakage points, caused by firstly pumping the mixture of rock debris and slurry into a drilling crew vibrating screen and then transporting to the recovery device, is effectively solved; and an environmental pollution risk is greatly reduced.

Second Preferred Embodiment

Referring to FIG. 1 and FIG. 2, a particle drilling method comprises steps of particle injection and particle recovery, wherein: the step of particle injection is to inject slurry and particles into a well through an injection device; the step of particle recovery is to enable a mixture of particles, rock debris and slurry returned from the well to directly flow into a recovery device by a pipeline through an exit device 28 at a well mouth of a drill floor with liquid energy, then send separated particles into a storage tank by a magnetic separator 10 of the recovery device, and send a mixture of rock debris and slurry into a slurry tank 11; after the steps of particle injection and particle recovery, the particles in the storage tank are transported to the injection device and injected into the well through the injection device for drilling again, so as to form a particle impact drilling circulation.

In the step of particle injection, a particle injection speed is 0.5 kg/s.

In the step of particle injection, a particle injection pressure is 5 MPa.

The injection device is a double-injection-pump continuous injection device, comprising a first hydraulic cylinder 1, a second hydraulic cylinder 2, a swinging hydraulic cylinder 3, a reversing pipe 4, a first piston 5, a first transporting cylinder 6, a second piston 7 and a second transporting cylinder 8, and further comprising a particle mixing hopper 25 which is connected with a drilling vertical pipe through a high-pressure pipeline 9, wherein: the reversing pipe 4 is arranged in the particle mixing hopper 25; the reversing pipe 4 is connected with the swinging hydraulic cylinder 3 which drives the reversing pipe 4 to swing from left to right; the particle mixing hopper 25 is connected with the first transporting cylinder 6 and the second transporting cylinder 7; the first hydraulic cylinder 1, the second hydraulic cylinder 2 and the swinging hydraulic cylinder 3 are firstly started; the first hydraulic cylinder 1 starts an addition stroke, the swinging hydraulic cylinder 3 swings the reversing pipe 4 to the second transporting cylinder 8 so that the reversing pipe is interconnected with the second transporting cylinder, and a mixture of particles and slurry enters the first transporting cylinder 6; meanwhile, the second hydraulic cylinder 2 starts a compression stroke that a mixture of particles and slurry in the second transporting cylinder 8 is injected into the high-pressure pipeline 9 through the reversing pipe 4 to enter an inner well circulation; the first hydraulic cylinder 1 starts a compression stroke after ending the addition stroke, and the second hydraulic cylinder 2 starts an addition stroke, so that a continuous injection is realized through an alternate operation.

According to the second preferred embodiment, when injecting the particles, the first hydraulic cylinder, the second hydraulic cylinder and the swinging hydraulic cylinder are firstly started; the first hydraulic cylinder starts the addition stroke, the swinging hydraulic cylinder swings the reversing pipe to the second transporting cylinder so that the reversing pipe is interconnected with the second transporting cylinder, and the particles and the slurry enter the first transporting cylinder; meanwhile, the second hydraulic cylinder starts the compression stroke that the particles and the slurry in the second transporting cylinder are injected into the high-pressure pipeline through the reversing pipe to enter the inner well circulation; the first hydraulic cylinder starts the compression stroke after ending the addition stroke, and the second hydraulic cylinder starts the addition stroke, so that the continuous injection is realized through the alternate operation, which guarantees a continuity of particle injection in the well, avoids the first transporting cylinder and the second transporting cylinder being blocked due to particle deposition, and effectively increases a working efficiency of particle impact drilling. In the double-injection-pump continuous injection device, merely the first transporting cylinder, the second transporting cylinder and the reversing pipe are in a high-pressure state, which greatly reduces a high-pressure area and improves safety.

Third Preferred Embodiment

Referring to FIG. 1, FIG. 3 and FIG. 4, a particle drilling method comprises steps of particle injection and particle recovery, wherein: the step of particle injection is to inject slurry and particles into a well through an injection device; the step of particle recovery is to enable a mixture of particles, rock debris and slurry returned from the well to directly flow into a recovery device by a pipeline through an exit device 28 at a well mouth of a drill floor with liquid energy, then send separated particles into a storage tank by a magnetic separator 10 of the recovery device, and send a mixture of rock debris and slurry into a slurry tank 11; after the steps of particle injection and particle recovery, the particles in the storage tank are transported to the injection device and injected into the well through the injection device for drilling again, so as to form a particle impact drilling circulation.

In the step of particle injection, a particle injection speed is 2 kg/s.

In the step of particle injection, a particle injection pressure is 20 MPa.

The injection device is a double-injection-pump continuous injection device, comprising a first hydraulic cylinder 1, a second hydraulic cylinder 2, a swinging hydraulic cylinder 3, a reversing pipe 4, a first piston 5, a first transporting cylinder 6, a second piston 7 and a second transporting cylinder 8, and further comprising a particle mixing hopper 25 which is connected with a drilling vertical pipe through a high-pressure pipeline 9, wherein: the reversing pipe 4 is arranged in the particle mixing hopper 25; the reversing pipe 4 is connected with the swinging hydraulic cylinder 3 which drives the reversing pipe 4 to swing from left to right; the particle mixing hopper 25 is connected with the first transporting cylinder 6 and the second transporting cylinder 7; the first hydraulic cylinder 1, the second hydraulic cylinder 2 and the swinging hydraulic cylinder 3 are firstly started; the first hydraulic cylinder 1 starts an addition stroke, the swinging hydraulic cylinder 3 swings the reversing pipe 4 to the second transporting cylinder 8 so that the reversing pipe is interconnected with the second transporting cylinder, and a mixture of particles and slurry enters the first transporting cylinder 6; meanwhile, the second hydraulic cylinder 2 starts a compression stroke that a mixture of particles and slurry in the second transporting cylinder 8 is injected into the high-pressure pipeline 9 through the reversing pipe 4 to enter an inner well circulation; the first hydraulic cylinder 1 starts a compression stroke after ending the addition stroke, and the second hydraulic cylinder 2 starts an addition stroke, so that a continuous injection is realized through an alternate operation.

The swinging hydraulic cylinder 3 comprises cylinder bodies 13, pistons 14, piston rods 15, a swinging rod 16 and a spline 17 connected with the swinging rod 16, wherein: the pistons 14 are connected with the swinging rod 16 through the respective piston rods 15; and the reversing pipe 4 is connected with the spline 17.

An arrow-shaped check valve 18 is connected with the high-pressure pipeline 9.

According to the third preferred embodiment, the swinging hydraulic cylinder comprises the cylinder bodies, the pistons, the piston rods, the swinging rod and the spline connected with the swinging rod, wherein the pistons are connected with the swinging rod through the respective piston rods; and the reversing pipe is connected with the spline. Through the swinging hydraulic cylinder having the above specific structure, the swinging rod enables the reversing pipe to change a direction flexibly, having an advantage of flexibly reversing; and moreover, through structures of the spline and the swinging rod, a service life is lengthened. The arrow-shaped check valve is connected with the high-pressure pipeline. With the arrow-shaped check valve, the mixture of particles and slurry is able to smoothly enter the well through the high-pressure pipeline; and, the mixture of particles and slurry is avoided reversely entering the first transporting cylinder or the second transporting cylinder, which effectively avoids a damage to people caused by a slurry leakage during a particle injection process and further improves safety.

Fourth Preferred Embodiment

Referring to FIG. 1, FIG. 3, FIG. 4 and FIG. 5, a particle drilling method comprises steps of particle injection and particle recovery, wherein: the step of particle injection is to inject slurry and particles into a well through an injection device; the step of particle recovery is to enable a mixture of particles, rock debris and slurry returned from the well to directly flow into a recovery device by a pipeline through an exit device 28 at a well mouth of a drill floor with liquid energy, then send separated particles into a storage tank by a magnetic separator 10 of the recovery device, and send a mixture of rock debris and slurry into a slurry tank 11; after the steps of particle injection and particle recovery, the particles in the storage tank are transported to the injection device and injected into the well through the injection device for drilling again, so as to form a particle impact drilling circulation.

In the step of particle injection, a particle injection speed is 6 kg/s.

In the step of particle injection, a particle injection pressure is 30 MPa.

The injection device is a double-injection-pump continuous injection device, comprising a first hydraulic cylinder 1, a second hydraulic cylinder 2, a swinging hydraulic cylinder 3, a reversing pipe 4, a first piston 5, a first transporting cylinder 6, a second piston 7 and a second transporting cylinder 8, and further comprising a particle mixing hopper 25 which is connected with a drilling vertical pipe through a high-pressure pipeline 9, wherein: the reversing pipe 4 is arranged in the particle mixing hopper 25; the reversing pipe 4 is connected with the swinging hydraulic cylinder 3 which drives the reversing pipe 4 to swing from left to right; the particle mixing hopper 25 is connected with the first transporting cylinder 6 and the second transporting cylinder 7; the first hydraulic cylinder 1, the second hydraulic cylinder 2 and the swinging hydraulic cylinder 3 are firstly started; the first hydraulic cylinder 1 starts an addition stroke, the swinging hydraulic cylinder 3 swings the reversing pipe 4 to the second transporting cylinder 8 so that the reversing pipe is interconnected with the second transporting cylinder, and a mixture of particles and slurry enters the first transporting cylinder 6; meanwhile, the second hydraulic cylinder 2 starts a compression stroke that a mixture of particles and slurry in the second transporting cylinder 8 is injected into the high-pressure pipeline 9 through the reversing pipe 4 to enter an inner well circulation; the first hydraulic cylinder 1 starts a compression stroke after ending the addition stroke, and the second hydraulic cylinder 2 starts an addition stroke, so that a continuous injection is realized through an alternate operation.

The swinging hydraulic cylinder 3 comprises cylinder bodies 13, pistons 14, piston rods 15, a swinging rod 16 and a spline 17 connected with the swinging rod 16, wherein: the pistons 14 are connected with the swinging rod 16 through the respective piston rods 15; and the reversing pipe 4 is connected with the spline 17.

An arrow-shaped check valve 18 is connected with the high-pressure pipeline 9.

Furthermore, the first hydraulic cylinder 1 and the second hydraulic cylinder 2 are both dual-rod hydraulic cylinders; two seal rings 19 are connected with the reversing pipe 4 and respectively arranged at two ends of the reversing pipe 4.

According to the fourth preferred embodiment, the first hydraulic cylinder and the second hydraulic cylinder are both dual-rod hydraulic cylinders, so that a uniform reciprocating motion is realized, synchronization between the addition stoke and the compression stroke is easily realized, and a stability of particle continuous injection into the well is improved, thereby guaranteeing a working efficiency of particle drilling. Two seal rings are connected with the reversing pipe and respectively arranged at the two ends of the reversing pipe. When the reversing pipe is interconnected with the first transporting cylinder or the second transporting cylinder, the seal rings are able to avoid a pressure leakage in the first transporting cylinder or the second transporting cylinder, so that the addition stroke and the compression stoke proceed stably and the particles are guaranteed to be smoothly injected into the well.

Fifth Preferred Embodiment

Referring to FIG. 1, FIG. 3, FIG. 4 and FIG. 5, a particle drilling method comprises steps of particle injection and particle recovery, wherein: the step of particle injection is to inject slurry and particles into a well through an injection device; the step of particle recovery is to enable a mixture of particles, rock debris and slurry returned from the well to directly flow into a recovery device by a pipeline through an exit device 28 at a well mouth of a drill floor with liquid energy, then send separated particles into a storage tank by a magnetic separator 10 of the recovery device, and send a mixture of rock debris and slurry into a slurry tank 11; after the steps of particle injection and particle recovery, the particles in the storage tank are transported to the injection device and injected into the well through the injection device for drilling again, so as to form a particle impact drilling circulation.

In the step of particle injection, a particle injection speed is 8 kg/s.

In the step of particle injection, a particle injection pressure is 40 MPa.

The injection device is a double-injection-pump continuous injection device, comprising a first hydraulic cylinder 1, a second hydraulic cylinder 2, a swinging hydraulic cylinder 3, a reversing pipe 4, a first piston 5, a first transporting cylinder 6, a second piston 7 and a second transporting cylinder 8, and further comprising a particle mixing hopper 25 which is connected with a drilling vertical pipe through a high-pressure pipeline 9, wherein: the reversing pipe 4 is arranged in the particle mixing hopper 25; the reversing pipe 4 is connected with the swinging hydraulic cylinder 3 which drives the reversing pipe 4 to swing from left to right; the particle mixing hopper 25 is connected with the first transporting cylinder 6 and the second transporting cylinder 7; the first hydraulic cylinder 1, the second hydraulic cylinder 2 and the swinging hydraulic cylinder 3 are firstly started; the first hydraulic cylinder 1 starts an addition stroke, the swinging hydraulic cylinder 3 swings the reversing pipe 4 to the second transporting cylinder 8 so that the reversing pipe is interconnected with the second transporting cylinder, and a mixture of particles and slurry enters the first transporting cylinder 6; meanwhile, the second hydraulic cylinder 2 starts a compression stroke that a mixture of particles and slurry in the second transporting cylinder 8 is injected into the high-pressure pipeline 9 through the reversing pipe 4 to enter an inner well circulation; the first hydraulic cylinder 1 starts a compression stroke after ending the addition stroke, and the second hydraulic cylinder 2 starts an addition stroke, so that a continuous injection is realized through an alternate operation.

The swinging hydraulic cylinder 3 comprises cylinder bodies 13, pistons 14, piston rods 15, a swinging rod 16 and a spline 17 connected with the swinging rod 16, wherein: the pistons 14 are connected with the swinging rod 16 through the respective piston rods 15; and the reversing pipe 4 is connected with the spline 17.

An arrow-shaped check valve 18 is connected with the high-pressure pipeline 9.

The first hydraulic cylinder 1 and the second hydraulic cylinder 2 are both dual-rod hydraulic cylinders; two seal rings 19 are connected with the reversing pipe 4 and respectively arranged at two ends of the reversing pipe 4.

Furthermore, a cross section of the reversing pipe 4 is “S”-shaped.

According to the fifth preferred embodiment, the cross section of the reversing pipe is “S”-shaped. Through the specific “S”-shaped reversing pipe, a reversing process becomes more flexible and convenient. The reversing pipe is able to rapidly connect with the first transporting cylinder or the second transporting cylinder, so as to guarantee a continuity of particle injection.

Sixth Preferred Embodiment

Referring to FIG. 1, FIG. 3, FIG. 4, FIG. 5 and FIG. 6, a particle drilling method comprises steps of particle injection and particle recovery, wherein: the step of particle injection is to inject slurry and particles into a well through an injection device; the step of particle recovery is to enable a mixture of particles, rock debris and slurry returned from the well to directly flow into a recovery device by a pipeline through an exit device 28 at a well mouth of a drill floor with liquid energy, then send separated particles into a storage tank by a magnetic separator 10 of the recovery device, and send a mixture of rock debris and slurry into a slurry tank 11; after the steps of particle injection and particle recovery, the particles in the storage tank are transported to the injection device and injected into the well through the injection device for drilling again, so as to form a particle impact drilling circulation.

In the step of particle injection, a particle injection speed is 10 kg/s.

In the step of particle injection, a particle injection pressure is 55 MPa.

The injection device is a double-injection-pump continuous injection device, comprising a first hydraulic cylinder 1, a second hydraulic cylinder 2, a swinging hydraulic cylinder 3, a reversing pipe 4, a first piston 5, a first transporting cylinder 6, a second piston 7 and a second transporting cylinder 8, and further comprising a particle mixing hopper 25 which is connected with a drilling vertical pipe through a high-pressure pipeline 9, wherein: the reversing pipe 4 is arranged in the particle mixing hopper 25; the reversing pipe 4 is connected with the swinging hydraulic cylinder 3 which drives the reversing pipe 4 to swing from left to right; the particle mixing hopper 25 is connected with the first transporting cylinder 6 and the second transporting cylinder 7; the first hydraulic cylinder 1, the second hydraulic cylinder 2 and the swinging hydraulic cylinder 3 are firstly started; the first hydraulic cylinder 1 starts an addition stroke, the swinging hydraulic cylinder 3 swings the reversing pipe 4 to the second transporting cylinder 8 so that the reversing pipe is interconnected with the second transporting cylinder, and a mixture of particles and slurry enters the first transporting cylinder 6; meanwhile, the second hydraulic cylinder 2 starts a compression stroke that a mixture of particles and slurry in the second transporting cylinder 8 is injected into the high-pressure pipeline 9 through the reversing pipe 4 to enter an inner well circulation; the first hydraulic cylinder 1 starts a compression stroke after ending the addition stroke, and the second hydraulic cylinder 2 starts an addition stroke, so that a continuous injection is realized through an alternate operation.

The swinging hydraulic cylinder 3 comprises cylinder bodies 13, pistons 14, piston rods 15, a swinging rod 16 and a spline 17 connected with the swinging rod 16, wherein: the pistons 14 are connected with the swinging rod 16 through the respective piston rods 15; and the reversing pipe 4 is connected with the spline 17.

An arrow-shaped check valve 18 is connected with the high-pressure pipeline 9.

The first hydraulic cylinder 1 and the second hydraulic cylinder 2 are both dual-rod hydraulic cylinders; two seal rings 19 are connected with the reversing pipe 4 and respectively arranged at two ends of the reversing pipe 4.

A cross section of the reversing pipe 4 is “S”-shaped.

Furthermore, the storage tank is a rotational storage tank 12, comprising a tank body 20, blades 21 arranged in the tank body 20, a support frame 22, a screen barrel 23 and a motor 24 driving the tank body 20 to rotate, wherein: the blades 21 and the support frame 22 are fixed on an inner wall of the tank body 20; the screen barrel 23 is connected with the blades 21 through the support frame 22.

Furthermore, the exit device 28 comprises a rotational sprayer 27 and a rotational control head 26 connected with the rotational sprayer 27.

According to the sixth preferred embodiment, the rotational storage tank comprises the tank body, the blades in the tank body, the support frame, the screen barrel and the motor driving the tank body to rotate, wherein: the blades and the support frame are fixed on the inner wall of the tank body; and the screen barrel is connected with the blades through the support frame. Through the rotational storage tank having the unique structure, when rotating positively, dynamic storage is realized, and the particles are avoided being agglomerated during a rotational storage process; when rotating negatively, particle discharging is realized, and the blades enable the particles to be uniformly discharged out. Through the step of particle recovery, the mixture of particles, rock debris and slurry returned from the well directly flows into the magnetic separator of the recovery device through the rotational control head 26 of the exit device 28 for particle separation, which simplifies a particle screening process. Because the slurry and the rock debris do not contain ferromagnetic materials, the particles are easily separated by the magnetic separator, having advantages of high separation efficiency and good separation effect. After separating the particles, the magnetic separator directly transports the separated particles to the storage tank for recycling. Compared with the prior arts, under a premise of not changing a conventional drilling process, a particle recovery process is simplified; devices which easily cause a slurry leakage, such as a jet mixer, an associated low-pressure pipeline, a vibrating screen and a rock debris storage hopper, are avoided; an installation efficiency, an operation convenience and a maintenance convenience of the recovery system are effectively improved; a working efficiency of particle impact drilling is greatly increased; a problem of many slurry leakage points, caused by firstly pumping the mixture of rock debris and slurry into a drilling crew vibrating screen and then transporting to the recovery device, is effectively solved; and an environmental pollution risk is greatly reduced. Through adopting the specific injection speed, performance of drilling fluid during the drilling process is guaranteed; and at the specific injection speed, a particle impact frequency of the particles hitting the rock is larger than 10 million times per minute, which achieves a good impact rock breaking effect and increases a drilling efficiency. Under the specific injection pressure, the injection speed of the particles is effectively guaranteed, the drilling efficiency is increased, a drilling vertical pipe is effectively avoided being damaged, and a working stability of particle drilling is guaranteed. 

1. A particle drilling method, comprising steps of particle injection and particle recovery, wherein the step of particle injection specifically comprises a step of injecting slurry and particles into a well through an injection device; the step of particle recovery specifically comprises steps of: enabling a mixture of particles, rock debris and slurry returned from the well to directly flow into a recovery device by a pipeline through an exit device at a well mouth of a drill floor with utilizing liquid energy; sending separated particles into a storage tank by a magnetic separator of the recovery device; and sending a mixture of rock debris and slurry into a slurry tank; and after the steps of particle injection and particle recovery, the particles in the storage tank are transported to the injection device and then injected into the well through the injection device for drilling again, so as to form a particle impact drilling circulation.
 2. The particle drilling method, as recited in claim 1, wherein in the step of particle injection, a particle injection speed is 0.5-10 kg/s.
 3. The particle drilling method, as recited in claim 1, wherein in the step of particle injection, a particle injection pressure is 5-55 MPa.
 4. The particle drilling method, as recited in claim 1, wherein: the storage tank is a rotational storage tank, comprising a tank body, blades arranged in the tank body, a support frame, a screen barrel and a motor driving the tank body to rotate; the blades and the support frame are fixed on an inner wall of the tank body; and the screen barrel is connected with the blades through the support frame.
 5. The particle drilling method, as recited in claim 1, wherein: the injection device is a double-injection-pump continuous injection device, comprising a particle mixing hopper which is connected with a drilling vertical pipe through a high-pressure pipeline; a reversing pipe is arranged in the particle mixing hopper; the reversing pipe is connected with a swinging hydraulic cylinder which drives the reversing pipe to swing from left to right; a first transporting cylinder and a second transporting cylinder are connected with the particle mixing hopper; when injecting the particles, a first hydraulic cylinder, a second hydraulic cylinder and the swinging hydraulic cylinder are firstly started; the first hydraulic cylinder starts an addition stroke, the swinging hydraulic cylinder swings the reversing pipe to the second transporting cylinder so that the reversing pipe is interconnected with the second transporting cylinder, and the particles and the slurry enter the first transporting cylinder; meanwhile, the second hydraulic cylinder starts a compression stroke that the particles and the slurry in the second transporting cylinder are injected into the high-pressure pipe through the reversing pipe to enter an inner well circulation; the first hydraulic cylinder starts a compression stroke after ending the addition stroke, and the second hydraulic cylinder starts an addition stroke, so as to continuously inject the particles through an alternate operation.
 6. The particle drilling method, as recited in claim 5, wherein: the swinging hydraulic cylinder comprises cylinder bodies, pistons, piston rods, a swinging rod and a spline connected with the swinging rod; the pistons are connected with the swinging rod through the respective piston rods; and the reversing pipe is connected with the spline. 7-8. (canceled)
 9. The particle drilling method, as recited in claim 5, wherein an arrow-shaped check valve is connected with the high-pressure pipeline.
 10. The particle drilling method, as recited in claim 6, wherein an arrow-shaped check valve is connected with the high-pressure pipeline.
 11. The particle drilling method, as recited in claim 1, wherein the exit device comprises a rotational sprayer and a rotational control head connected with the rotational sprayer. 